If the slide-throttle was installed Upstream of the plenum it would work
fine. But this would make no sense for the slide-throttle that Paul
designed. It is a two-holer designed to be installed right
next to the engine ports (P-ported engine). A single hole would be
the best for an upstream design.
FWIW, I don't get the whole rational for the slide-throttle. True, it
it theoretically the best performing solution but I live in the real world where
the small theoretical advantage is outweighed by other factors.
TJ, I forgot to comment on the FBW. It is near (near being a
relative term : ) production status but the hold modes are still being
worked on and will not be finished before the RV-8 flys and it has been flight
proven. I don't sell flight critical stuff that I haven't risked
my own tender pink skin on first.
Tracy (Last EC2 update out the door, departing for Colorado Tuesday)
----- Original Message -----
Sent: Saturday, May 12, 2007 3:49
PM
Subject: [FlyRotary] Re: EC2 smoke
question
Hi Tracy,
thanx for screening the smoke!
I already thought so (you wouldn't be selling, if your product would not
work....).
Just wanted the scope on the smoke-machine, it is always entertaining at
the least, but mostly also very educational - technically and human relations
wise:)
As far as his slide-throttle p-port goes:
P-port should not be a hindrance to install a manifold-plenum or is
there something I don't see??
TJ
Hi TJ,
Smoke is very hard to clear up. Visibility here in Fla was
less than 1/4 mile all day. I thought it was the fires in Georgia
& N. Florida but it is possible that it was from a certain Email list
purveyor in California :-0
Seriously, the C/S prop story about not being compatible with the EC2
is just that - Smoke. The engine load is
accurately reflected by Manifold pressure and RPM. These are the
primary inputs to the EC2 so it has no problem tracking the variations
caused by a CS prop. I don't have the time to elaborate but it is
actually harder to match the fuel requirements of a fixed pitch prop in
most circumstances. The changes in volumetric efficiency due to rpm
change are eliminated with a CS prop.
The full story about the "Dyno incompatibility" is a longer one which I
will abbreviate out of necessity.
It started with Paul's trip to Mazdatrix to test Mark Supenski's
P Port engine with his beloved slide throttle (which had never run
before). As it happens, there is no manifold on an engine in
this configuration so it is difficult to measure manifold pressure.
Where are you going to get manifold pressure from? (did I mention that
manifold pressure was a primary input to the EC2?) To make matters
worse, Paul was so confident in his abilities to make anything work (even an
EFI system that he had zero experience with) that he didn't bother
to take the EC2 instructions with him to Mazdatrix. Given
these circumstances, it was no surprise that the dyno run was a dismal
failure. Dave at Mazdatrix yanked everything off the engine, put a
webber carb and manifold on it and got it running in order to get a pull on
the dyno.
And so the story of how the EC2 will not run on a Dyno (and by
extension, with a CS prop) was born.
Tracy